Manufacture of sulfuric acid



JAMES HERBERT BRUN/VN, OF MANCHESTER, ENGLAND.

MANUFCTURE OF SULFURIC AC'D.

igarasei.

l Application filed July 16,

To all irl 01u-'it fm oj/ concer/u -l'e `it known that l. Janes l'linnanrr .BnowN7 a subject of the King oil Great llritain, resiiling at lllanchester, in the county 0l Lancaster and ,Kingdom ol England, have1 invented. certain .new and uselul improvementsin lllanulfacture ol blulluricliicid, of whichthe following a speciiication.

i 'l his invention relates to an improved proce and plant 'lor the manillar-ture olf sulfuric acid by the chamber or like process. lt is the object of the invention to 'iroi'luee a clean and pureacid direct eren when starting i troni arsch ical fumes.

lf` mechanical burners are employed the quantity ol dust carried by the burner gases is large, and this dust .is not removed by the usual dry dust chambers. Ciniseqneutly the acid 'in the Glover tower is made ver i dirt a and when arsenical pyrites are used.) highly arsenieal. lt is therefore diliixted, dearsi-:nicated and,re-concentrated.I The present in-Y vention aims at overcoming these dilliculties. 'According to the invention in its liireferred .liorml,a burner, particularly a mechanical burnerwis combined with a dust chamber, a wash tower led with acid o'l' about i000 to y 140 Tw. two filters oil:x graded coke, a. hin, a smallcole box, prele'ably fed withstrone acid9 a' heat interchanger heated by the dust chamber, a gas heater, and a Glover tower after which the gases pass forward to the lead chambers in the usual wayA The words chamber plant are'nsed in the specification and claims las including any plant in which sulfuric acid is formed from sulfur dioxid water and oxygen by the agency of loxids of nitrogen; thus the expression chamber plant `will be used for brevity to include plants in which all the chambers ,are replaced by towers in ltnown mai1ne1,.ancl so on. l

In the accompanying drawings, Figure l s a diagrammatic plan of the plan@ Figs. 2 and 3 are diagrammatic views in plan and elevation ol a di'stributer.` j

The burner gases leave the burner A.

which is shown as a mechanical burner, and

enter thc'dust chamber which is provided with bailles or circuitons passages in any linown manner. The dust chamber consi ,s of two parts ld and C and a by-pass ll." is provided to cut ont the portion B if desired. D is the wash tower which is preferably oi about the same size as an ordinary Glover Specification of Letters Patent.

`Patented Jan. 18;, 1921.

1918. serial No. 245,242..

tower, andconstructed in substantially the sainemanner, except that a special distribir ter is provided as shown more fully in Figs. 2 and 3, Down the wash tower is circulated the washing fluid (preferably acidoi about 1 0()O to M00 'l`w.:l.500 1101.700 spec. gravity) by suitable elevators or pumps. Other washing means may be employed lif desired. From the wash tower l) the gases pass' through two lilters E and F in series. These filters may bepached with colte graded in size, coarse at the bottom and line on top;

i the gases preferably pass dmvnward through the coke. ll'lanholes Q, are provided in the loi-in of lnted lead bells for the purpose of cleaningvr.` The gases are then led to a fan or blower (il from which'they pass through a small colo-scrubber ll to remove drops ot acid condensed bythe lan. lt is advisable to allow a trickle ol strong,` acid (say 1500 rlw. or upwarfll to run down this scrubber in order to dry the gases further, so to protect the `iron pipes l .which pass through the dust chamber and arc heated by the hot burner gases. A, bypass L provided so that the rases .may be caused to miss the heater pipes l it' desired; they then enter the gas healer lll which may be of any known type, and pass therefrom through an upshal't hl containing the potting; oven, to a Glover tower U. The gases leave the Glover tower at lJ and enter they chambers and finally the Gay Lussac towers in the ordinary manner.

lll it is desired to cut out the heat-inter changer pipes il, this can be done by closing dampers in the mains and opening dampers in the lay-passes; li and L. The lian (l is best` placed as shown though il" it is desired to jirotect the 'lau still further, it may be placed alter the scrubber ll Iled with Jfairly strony,r acid; the rases entering' the fan will then be reasonably dry; in this case however itwill be advisable to place' a small eolie scrubber (which need not be ied with acid) between 'the lan and thepipes il to catch any coniilensatcf In some cases the li'an maybe placed lfietween the dust chamber and the i wash tower, or between the heat interchange pipes l and the sg-as heater, but the fan will llico be dealing with hot rases and the me chanical dilliculties ot working are thereby increased considerably.

The dust chamber removes much 'of the dust but a ,large amount vis removed by the .wash tower, and the Wash acid therefore contains much dissolved and suspended iinpurity. From time to time thisacid 1s settled in tanks, and the clear liquor separated from the sludge. It is found however that the acid entering the top of the Wash tower soon chokes in the usual forms of dise,

tributer and therefore a special distributer `is provided of such dimensions and form forms of distributer can be employed but the important point to note is that the distributers must be of such form that they cannot become choked by the impurities which either settle out or crysfallize out from the wash acid.

The wet coke filters remove the final traces of arsenic from the cooled gases, and it is found in practice that by this process and plant it is possible to produce Glover towel" acid of high strength which is water-white and is dcarsenicated down to say 5 to 10 parts per million or less eren when using arsenical pyrites.

l declare that what I claim is:-

1. The combination with a chamber plant of a burner, means for washing the burner gases and reheating the washed gases prior to oxidation.

2. The combination with a chamber plant. of a burner, means for washing the burner gases, means for filtering the gases and means for reheating the purified gases prior Ato oxidation.

El. The combination with achamber plant of a burner, a dry dust collector. means for washing the gas, means for filtering the gas,

and means for reheating the purified gasprior to oxidation.

Jr. 'l`hecoinl 'nation with a chamber plant of a burner, means for washing the burner gases. and a gas healer to re-heat said gases prior to oxidation.

5. The combination with a chamber plant of a burner` a wash tower for the burner gases, means to reheat the burner gases, and

means for delivering the washed and re- I a chamber plant.

7. The combination of a burner, means for cooling and lpurifying the burner gases, means for drying the purified gases, means for reheating the purified gases, and a chamber plant receiving the gases thus prepared.

8. The combination of a burner, a wash 'tower'for washing the burner gases, and

means to distribute the wash acid, over the packing of said tower, said distributing means comprising pipes and distributer surfaces so ar 'anged and of such dimensions as toy prevent choking by deposition or c'rystallization of impurities, with means for reheating the washed gases, and a chamber plant.

S). process of manufacturing sulfuric acid which includes the steps o fwashing, filtering and reheating burner gases before passing theminto a concentrating and denitrating zone.

10. process of manufacturing sulfuric acid which includes the steps of 'ashing the burner gases with acid of about 100 t0 140 Tw., filtering the washed gas and reheating the filtered gas before passing them into a concentrating and denitrating zone.

1l. A process of manufacturing sulfuric acid which includes the steps of washing. the burner gases and reheating said purified gases before passing them into a concentrating and denitrating zone.

12. A lprocess of manufacturing.sulfuric acid which includes the steps of washing and filtering the burner gases, and reheating said filtered gases by the hot burner gases before passing said gases into a concentrating and denitrating zone.

13. process of manufacturing sulfuric acid which includes the steps of wet'filtra` tion of the burner gases and reheating said gases before passing them' into a concentrating-and denitrating zone.

ln witness whereof` l have hereunto signed my name this 25th day Aof June, 1918, in the presence of two subscribing witnesses. JAMES HERBERT BROlVN. Witnesses:

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